Author and Astrophysicist

Blogging the Feynman Lectures

I’m trying something new here, starting with this post: I’m blogging the Feynman Lectures on Physics, chapter-by-chapter (approximately). For those of you unfamiliar with the Feynman Lectures, they’re a classic set of introductory college physics lectures given by the great Richard Feynman 50 years ago at Caltech, compiled into book form. But despite their provenance, the books are not really introductory. They’re more like a rite of passage for advanced students within the field. One of my professors in college actually did assign the Feynman Lectures as supplementary texts for his intro-level class, but he explicitly said that they were “not really for the beginning student — but every good physicist, at some point or another, should read the Feynman Lectures.”

Here’s my dirty little secret: I’ve never read the Feynman Lectures. Sure, I’ve got a set — I bought them for that introductory class back in college — and I’ve used them as a reference, but I’ve never actually sat down and read them, cover-to-cover. There just never seemed to be the time while I was taking classes and doing research. But now that I’m a true freelance astrophysicist, adrift in the world outside of academia, I’m not immersed in physics every day of the week any more — and I miss it. So what better time to sit down and learn from the master?1 And with the 50th anniversary of the printed Lectures coming up in June, blogging them seemed like a natural choice. So, starting this week, I’ll be posting here about one or two chapters at a time from Volume I of the Feynman Lectures on Physics, with the tag FLoP. The subtitle for the volume is “Mainly Mechanics, Radiation, and Heat”: that covers an awful lot of ground that I really enjoy, from special relativity to statistical mechanics to symmetries in physical laws. Those subjects leave a lot of room for creative and interesting physical explanations at the lay level, which is what this blog is all about.

This week, though, I’m going to start by looking at the front matter: the introduction and the foreword. Given the legendary reputation that these lectures have acquired over the last 50 years, both Feynman’s preface and the original foreword by Robert B. Leighton are quite remarkable in how circumspect they are about the quality of the content. Feynman’s preface, in particular, leaves me with the impression that he was unhappy with how the course turned out. Feynman says that the “one serious difficulty” in teaching the course was the lack of a mechanism by which the students could give him feedback about the lectures (a problem we certainly don’t have these days, with our abundance of automated course feedback forms). He goes on to say that this was particularly problematic towards the end of the course: “the quantum mechanics part [Volume III] was not completely successful — in large part because I really did not have enough time at the end….Also, I had never presented the subject this way before, so the lack of feedback was particularly serious.” He didn’t think he did a good job of teaching introductory physics: “My own point of view…is pessimistic. I don’t think I did very well by the students. When I look at the way the majority of the students handled the problems on the examinations, I think that the system is a failure.” Finally, he ends by questioning the efficacy of lectures in general, and setting out a fairly modest goal for the printed lectures: “It’s impossible to learn very much by simply sitting in a lecture, or even by simply doing problems that are assigned….Perhaps in some small place where there are individual teachers and students, they may get some inspiration or some ideas from the lectures. Perhaps they will have fun thinking them through — or going on to develop some of the ideas further.”

Leighton’s foreword is largely about how the course came to be, and how the tape-recorded lectures were turned into the printed books. He, too, is very modest about the books, almost to the point of issuing a disclaimer: “we were forced to aim toward a preliminary but technically correct product that could be used immediately, rather than one that might be considered final or finished….We have no illusions as to the completeness, smoothness, or logical organization of the material…” Of course, all of this does go along with what I’ve always heard about these lectures: they’re not really introductory at all, and never were. But it’s still somewhat jarring to see such self-deprecation in what’s generally acknowledged to be such a mighty work.

Finally, both Feynman and Leighton point out that there was material in the course that doesn’t show up in the printed lectures. Feynman mentions three lectures early in the course on how to solve problems, which don’t appear, and a lecture on inertial guidance which is also missing. Leighton says that “the exercises are published separately in a less permanent form in order to encourage frequent revision.”2 I believe that some or all of this material has been compiled and published in the last few years, but I don’t have it — in fact, I’ve somehow got the 25th Anniversary Commemorative Edition, blue hardcovers rather than the classic red softcovers. I’m not sure how I ended up with an edition from 1989 when I bought it in 2003, but so it goes. So for those of you following along at home (hi Lian!), keep in mind that I’m probably working from a different edition than you are.

That’s the front matter of the Feynman Lectures. Next week: particle physics, burning diamonds, and the most important fact in science.

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3 thoughts on “Blogging the Feynman Lectures”

I look forward to seeing the posts! I’ve also read bits and pieces here and there but never read the whole thing through. Sounds like a fun project! My version is red hardcovers and I have a fourth book “tips on physics” which might have some of the bonus info.

I am a community college student ( in California) that just finished my introduction to physics courses (calculus based). I just bought the Feynman lectures and I can not wait to read them. I hope it is not to advance for me. I have already finished all my math classes for a physics major.